Cu2+胁迫对2种速生柳幼苗生长及生理特性的影响

摘要

In order to evaluate the potential of phytoremediation application of fast-growing willows, we investigated the growth and the changes of some physiological indexes for seedlings of Salixjiangsuensis CL J-172 and Salix babylonica grown in hydroponic solution under different copper concentrations. The results showed that the biomass, chlorophyll contents in leaves, root activities and root morphology indexes decreased obviously as copper concentration increased. The activities of SOD,POD and proline contents first increased and then decreased as the copper concentration increased. The activity of SOD in S. jiangsuensis CL J-172 and S. babylonica reached the highest value when the copper concentration was 20 μmol · L-1 , the activity of POD reached the highest value when the copper concentration were 100 μmol · L-1 for S. jiangsuensis CL J-172 and 40 μmol · L 1 for S. babylonica and the proline content reached the maximum when the copper concentration was 200 μmol · L-1, It could be concluded that the growth of two species of willows were both inhibited by copper stress,they can increased the SOD activity,POD activity and proline content to resist this stress,and S. jiangsuensis CL J-172 had better endurance than S. babylonica.%以营养溶液中培养的'苏柳172'(Salix j iangsuensis CL J-172)和垂柳(Salix babylonica Linn)幼苗为材料,分析它们在不同浓度Cu2+溶液(0、20、40、80、100、200、300 μmol·L-1)下的生长以及部分生理指标的变化,以明确2种速生柳树用于植物修复的潜力.结果显示:2种柳树幼苗的生物量、叶片色素含量、根系活力以及根系形态的各指标都随Cu2+浓度的增加而显著降低.它们叶片SOD和POD活性以及脯氨酸含量随Cu2+浓度的增加呈先上升后下降的趋势,'苏柳172'和垂柳中SOD活性在Cu2+浓度为20μmol·L-1时最大,其POD活性分别在Cu2+浓度为100和40 μmol·L-1时达到最大,而其脯氨酸含量在Cu2+浓度为200μmo1·L-1时达到最大.可见,2种柳树生长均受到Cu2+胁迫的抑制,它们能够在一定程度上通过增加保护酶活性和脯氨酸含量来提高对Cu2+的耐受性,且'苏柳172'对Cu2+的忍耐力强于垂柳.